Spun roving apparatus



Jan. 21, 1964 G. E. BENSON sPuN ROVING APPARATUS 2 Sheets-Sheet 1 Filed May 5, 1961 INVENTOR. Gusmv E. BENSON Y QM Jan. 21, 1964 e. E. BENSON spun 'ROVING APPARATUS 2 SheetsSheet 2 Filed May 3, 1961 INVENTOR. Gusmv E. BENSON BY m QM 147' TORA/EYS United States Patent 3,118,213 SPUN ROVER} APPARATUS Gustav E. Benson, Greenville, R.I., assignor to Owens- Corrr ng Fibergias Corporation, a corporation oi Delaware Filed May 3, 1961, Ser. No. 107,547 4 Claims. (Cl. 28-1) This invention relates to improved apparatus for use in the production of spun roving and more particularly to a spun roving cone carrying loop-forming projections by means of which better roving can be produced.

Spun roving, particularly made of glass fiber strands, is now well known in the art and is employed in many applications. Although spun roving has been made for a number of years by the rnehod disclosed and claimed in Slayter Patent 2,719,352, there has been a continual search for an apparatus which will produce improved, more uniform roving which has the advantages of higher strength and of better appearance. While a number of different apparatuses have been proposed and tried for making spun roving from strands of glass or the like, the product usually contains more twists and loops along some portions than along others; as .a consequence, the roving varies in diameter and strength along its length.

The present invention relates to apparatus which is capable of producin uniform roving of predetermined size and strength. The new apparatus includes wall means forming a hollow, truncated cone, into a large end of which strand is injected continuously. The cone contains at least one projection afiixed to the inner surface thereof, which projection extends inwardly almost to the center of the cone. The cone and the projection are rotated to cause the projection to intersect the injected strand once during each revolution of the cone, thereby causing the strand to form loops by being doubled back on itself, as will be more apparent subsequently. The loops are then pulled through a small end of the cone by suitable winding apparatus and are twisted into a uniform roving product as they move out of the small end of the cone. In a preferred form of the invention, a blower adjacent the small end of the cone directs jets of air toward the roving, tending to cause ends of the loops to be tucked into the roving and to cause further intermingling of the individual strand loops. The new roving apparatus enables the strand loops to be formed and twisted in one operation and in only one piece of apparatus. The loop-forming projections in the cone not only form the strand loops but hold them in uniform relationship in the cone until they are partly pulled into the roving. Thus, the loops cannot slide on the inner surface of the cone which not only piles them nonuniformly in bunches but tends to nullify twist which is imparted to the roving, because the loops slide in the direction of twist. Also, because the loops are pulled from the projections rather than being thrown therefrom, the point of separation of the loops and projections is more accurately controlled. The roving is also pulled from the cone in the same direction that the strand enters it, and from the opposite end, so that there is substantially no opportunity for the roving to become entangled with the entering strand. in addition, where the projections are in the form of twisted vanes, they can be designed to overcome the ilow of air upwardly through the cone which is inherent therein.

The term strand as used herein is intended in the broad sense to include a multiplicity of filaments grouped together in generally parallel relationship, single relatively heavy filaments, or thread or yarn made from twisted filaments. Basically, the strand must be of a generally continuous nature and sufficiently flexible to 3,li,2l3 Patented Jan. 21, 1964 2 be relatively easily doubled back into loops. The invention is not limited to roving made of strands of glass fibers.

It is, therefore, a principal object of the invention to provide apparatus for producing spun roving of improved uniformity.

Still another object of the invention is to provide apparatus for producing spun roving which apparatus includes means for forming loops in a strand from which the roving is made and means upon which the loopforming means are mounted for directing and twisting the looped strand so formed.

Yet another object of the invention is to provide apparatus for producing spun roving, which apparatus can be closely controlled to produce spun roving of predetermined size and twist and has the additional advantages outlined above.

Other objects and advantages of the invention will be apparent from the following detailed description of preferred embodiments thereof, reference being made to the accompanying drawings, in which:

FIG. 1 is an over-all, somewhat schematic view in elevation of apparatus for producing glass filaments, for gathering the filaments into strands, doubling and twisting the strands into spun roving by a cone embodying the principles of the invention, and for winding the rov- 111g;

PEG. 2 is a greatly enlarged view in vertical cross section of the roving-producing cone and a blower shown in FIG. 1, strand being shown in the cone;

FIG. 3 is a top view of the cone shown in FIG. 2;

FIG. 4 is a view in horizontfl cross section taken along the line 4-4 of FIG. 2;

FIG. 5 is a view in vertical cross section of a slightly modified cone embodying the principles of the invention; and

FIG. 6 is a top view of the cone shown in H6. 5

Referring to the drawings, and more particularly to FIG. 1, the over-all apparatus from which glass spun roving is made includes a bushing 12., a size applicator 14, an idler 16, a pulling wheel 18, spun roving apparatus 2%, a blower 22, and a winder 24.

The bushing 12 can be any of a number of types which are well known in the glass fiber art. Basically, the bushing includes a chamber in which glass is melted and a plurality of bushing tips 26 containing orifices through which glass is pulled and attenuated into filaments 28 by means of the pulling wheel 13. The individual filaments 28 are coated with a suitable size which is applied thereto by means of the applicator 14 which can comprise a roller onto which the size is flowed. The coated filaments are then gathered and carried as a strand 3d over the pulling wheel 18. The pulling wheel 18 can be any of several types known in the art but is preferably of the single wheel type employing a plurality of slots and having a separate hub with spokes which me synchronized with the wheel and which extend through the slots at predetermined peripheral positions on the wheel to eject the strand 3t] therefrom. A pulling wheel of this type is shown in more detail in Russell Patent No. 2,863,358, dated January 13, 1959. This type of pulling wheel is particularly advantageous because it ejects the strand in a straight line with substantially no flutter and thus enables the strand to enter the apparatus 2% at a substantially fixed point at all times.

The roving-forming apparatus 2% includes a hollow, truncated cone 32 (FIGURE 2) which forms an included angle of approximately 15 although this can be somewhat larger or smaller. Near a larger end of the cone 32 are several projections or pins 34, three being shown in FIGS. 2 and 3, which extend close to the center of the cone and at an angle of 45 to the horizontal or vertical. The pins 34 are inserted into the openings 36 (FIG. 2) of the cone 32 from the outside thereof and have enlarged heads 38 which properly locate the pins 34 in the cone. A collar 46' is attached to the large end of the cone 32 by screws 42 or other suitable means, the collar 40 including headless screws 44 which abut the heads 38 of the pin 34 and maintain them snugly in position.

An outer cylindrical portion 46 at the lower end of the cone 32 receives bearings 48 through which the cone is rotatably' supported, and a sheave 56* for driving the cone. The sheave 50 is driven in this instance, by means of a timing belt 52, a drive sheave 54, and a motor 56.

As the cone 32 is rotated, it carries the pins 34 which intersect the path of the strand 30 once during each revolution. As the pins 34 cut across the path of the strand 30, the strand is looped over them and continues to move downwardly therebeyond until another pin is contacted, thereby forming a lower loop end. Newly formed lower loop ends, such as loop ends 58 in FIG. 2 lie on the previously formed loops whereas upper ends 60 usually lie outside of previously formed loop ends, the previously formed loop ends moving inwardly and downwardly on the pins 34 as their associated lower loop ends are pulled and twisted into a roving 62 which is being formed at the smaller end of the cone 32. Thus, the lower loop ends 58, being positioned on the previously formed loops, lie at the center portion of the roving 62 Whereas the upper loop ends 60, being outside the previously formed loops, lie at the outer surface of the roving 62. on the pins 34 which hold the loops in uniform, spaced relationship and prevent them from sliding on the inner surface of the cone 32. As the lower loop ends 58 are deposited on previously deposited loops of strand in the cone 32, they are pulled downwardly therewith and are drawn into the center portion of the roving, pulling the upper ends 60 of the strand downwardly and inwardly off the pins 34, the longitudinal pull on the upper ends 60 overcoming the centrifugal force exerted thereon by rotation of the cone 3 2. The strand loops are also twisted as they are pulled through the cone 32, because the roving 62 exiting from the cone is stationary while the upper loop ends 60 are rotating with the cone 32 and the pins 34 at relatively high speed.

The blower 22 at the small end of the cone 32. includes an air supply pipe 66 (FIGS. 2 and 4), a manifold chamber 68, and four radially disposed slots 76 which extend longitudinally of the roving 62. Air supplied to the chamber 68 is emitted at high velocity through the narrow slots 70 and tends to tuck in the loop ends 60 at the surface of the roving 62. This air has little effect upon most portions of the strand in the roving 62 because its travel is generally parallel to most portions. However, the loop ends 60 cross the paths of the air streams and thus tend to be blown into the roving between the generally parallel portions of the strand. Other means can be employed to tuck in the upper loop ends of the strand such as a plurality of fins extending radially inwardly in the position now occupied by the slots 7%). However, the high velocity air has been found to be the most effective. Of course, the roving 62 can be made without the use of any means at all below the cone 32 to tuck in the upper loop ends and to cause further intermingling of the strand, although better roving is produced with such means.

By increasing the air pressure sutficiently in the chamber 68, the strand constituting the roving as can be spread apart or filamentized so that it tends to be separated into its individual filaments. This gives the roving a fiuify or texturized effect and considerably increases the bulk thereof.

A slightly modified roving-forming apparatus 72 is shown in FIGS. and 6. This apparatus i cludes a cone 32, substantially the same as the corresponding cone 32 in FIG. 2, and projections or fins 74, which take the place of the pins 34. The fins 74 are welded or otherwise suitably attached to the interior of the cone 32 and are of shallow helical shape to provide a slight flow of air from the large end of the cone 32 to the small end thereof as the cone and the fins are rotated. This downward flow of air counteracts an upward fiow of air which is inherent in any hollow conical member rotated at high speed, centrifugal force acting on the air therein which throws it outwardly and upwardly along the surface toward the large end of the cone. The fins 74 otherwise act in the same manner as the pins 34 of FIGS. 2 and 3, strand (not shown) being caused to loop over upper edges 75 of the fins 74 as the fins intersect the path of the strand. The fins have the advantage that they provide slighhy more positive twist in the resulting roving, this occurring because the strand, after leaving the upper edges '76 of the fins 74, cannot slide around the cone as can happen to some extent in the cone 32 of FIG. 2. However, the apparatus 72 is more difiicult to fabricate and the upper edges 76 of the fins 74- also tend to wear quite rapidly due to an erosive effect of the glass strand. The pins 34- tend to wear to a much less rapid extent than the fins '74 and can be replaced easily when necessary. For these reasons, the apparatus 2i? is preferred to the apparatus 7 It may be noted that the apparatus '72 can be used with the blower 22 or other device to tuck in the loops.

The above discussion and the accompanying drawings, particularly where pertaining to the position of the strand in the cone, is presented only for purposes of illustration and not limitation. The roving 62 also is shown in but one form and can be changed considerably by varying the amount of twist in the roving and the length and number of loops therein.

The number of loops, loop length, and amount of twist in the roving can be closely controlled with the apparatus according to the invention, each of these values being approximately determined by the following formula:

where: S=speed of the cone in r.p.m., R=rate of lineal movement of the strand injected into the cone in f.p.m., n=number of pins in the cone, and L loop length in inches. From this formula it can be seen that the speed of the cone and the rate of lineal movement of the strand are directly proportional and can be increased or decreased proportionally in order to maintain loop length and number of loops constant. In addition, for constant rates of movement of the strand and of rotation of the cone, the number of fins determines loop length and also number of loops. As another point, twist may be increased by using fewer projections and additional rotational speed with a constant loop length. Thus, by using only one projection rather than two, and by doubling the speed of rotation, the same number of loops and the same loop length will result but the twist will be approximately doubled because the speed of the cone is doubled, the

rate of lineal movement of the strand remaining the same.

The length of the loops should be approximately equal to the distance from the projections in the cone to the smaller end thereof because if the loops are longer than this distance, they will tend to ball up or plug at the small end of the cone and if they are shorter than this distance, they will tend to feed in properly through the small cu s. Also, the rate of lineal movement of the finished roving, as determined by the speed of the winder 2 which can be of any suitable type, should equal the rate of formation of the roving to prevent it from jamming at the blower 22 or the small end of the cone 2% and also to prevent it from being pulled apart by excessive lineal speed.

In a specific embodiment of the invention, the filaments 28 are attenuated from the tips 2a; of the bushing 12 at a rate of 12,009 feet per minute with the cone 32 rotated at a speed of 3000 rpm. Two projections or pins 34 are located in the cone to provide a inch loop length, this distance also being the distance between the pins 3-; and the small end or" the cone 32.

Various modifications of the above described embodiments of the invention will be apparent to those skilled in the art and it is to be understood that such modifications can he made without departing from the scope of the invention, it within the spirit and tenor of the accompanying claims.

I claim:

1. Apparatus for producing roving which comprises hollow wall means having a large end and a small end, at least one projection attached to said wall means and extending inwardly therefrom toward an axis of said wall means, means for supporting and rotating said wall means about the axis, means for injecting a strand into the lags end of said wall means in a position where it wiil be intercepted by the projection during rotation of the wall means, means for puliing the strand on the projection and through the srr 1 end of said wall means, means comprising a plurality of air jets adjacent the small end of said wall means for exerting a radially inwardly directed force on the roving, said force extending longitudinally over a portion of the length of the roving to push inwardly loops at the surface thereof.

2. Apparatus according to claim 1 wherein said projection is a vane extending generally longitudinally of the wall means.

3. Apparatus for producing roving which comprises hollow wall means having a large end and a small end,

means for supporting and rotating said wall means about an axis, means for projecting a strand toward the large end of said wail means, loop-forming projections for intersecting the strand and forming it into loops in the wall means, means for pulling the looped strand through the smail end of said wall means, and means adjacent the small end of said wall means for establishing a plurality of air jets directed inwardly toward the resulting roving and extending over a portion of the length thereof for exerting a plurality of spaced radially inwardly directed forces on the roving to push inwardly loops at the surface thereof.

4. Apparatus for producing roving which comprises lioliow wall means having a large end and a small end, means for supporting said wall means on an axis, means for projecting a strand toward the large end of said wall means and for looping the strand, means for pulling the looped strand through the small end of said Wall means, biower means adjacent the small end of said wall means, said blower means comprising means forming a manifold chamber, means forming a plurality of radially disposed, inwardly directed, and circumferentially spaced slots extending longitudinally of the axis of said wall means, and means for supplying air to said manifold chamber to emit air jets at high velocity through said slots.

References Qited in the file of this patent UNITED STATES PATENTS 

1. APPARATUS FOR PRODUCING ROVING WHICH COMPRISES HOLLOW WALL MEANS HAVING A LARGE END AND A SMALL END, AT LEAST ONE PROJECTION ATTACHED TO SAID WALL MEANS AND EXTENDING INWARDLY THEREFROM TOWARD AN AXIS OF SAID WALL MEANS, MEANS FOR SUPPORTING AND ROTATING SAID WALL MEANS ABOUT THE AXIS, MEANS FOR INJECTING A STRAND INTO THE LARGE END OF SAID WALL MEANS IN A POSITION WHERE IT WILL BE INTERCEPTED BY THE PROJECTION DURING ROTATION OF THE WALL MEANS, MEANS FOR PULLING THE STRAND OFF THE PROJECTION AND THROUGH THE SMALL END OF SAID WALL MEANS, AND MEANS COMPRISING A PLURALITY OF AIR JETS ADJACENT THE SMALL END OF SAID WALL MEANS FOR EXERTING A RADIALLY INWARDLY DIRECTED FORCE ON THE ROVING, SAID FORCE EXTENDING LONGITUDINALLY OVER A PORTION OF THE LENGTH OF THE ROVING TO PUSH INWARDLY LOOPS AT THE SURFACE THEREOF. 